EP0121606A1 - Process for the preparation of shock-resistant polyamide mouldings by alcaline lactam polymerisation - Google Patents

Abstract

The invention relates to a method for producing impact-resistant polyamide molding compositions by activated alkaline lactam polymerization. The polymerization is carried out in the presence of a graft polymer in which on A. 5 to 95 parts of a rubber-like polymer with a glass transition temperature below 0 ° C., B. 95 to 5 parts of a polyadduct, a polycondensate or an acrylic polymer which has a glass transition temperature above 0 ° C, and optionally C. 0 to 90 parts of a vinyl monomer are grafted.

Description

The invention relates to a process for the production of polyamide molding compositions by activated anionic lactam polymerization. This is known per se and is described, for example, in Kunststoff-Handbuch, Volume VI, Polyamide, Carl Hanser Verlag 1966, pages 46 to 49. Two components I and II are assumed, component I being a lactam melt containing a catalyst and component II being a lactam melt containing an activator. The two components are mixed, transported into a mold and polymerized there. This can also be done according to the reaction injection molding (RIM) process known from polyurethane technology.

Despite the excellent properties of the ALP polymer, the impact strength and the elongation at break are unsatisfactory for many purposes.

Several attempts are known to improve these properties. So, e.g. in DE-A 22 48 664, to improve the impact resistance by admixing high molecular weight polyalkylene glycols to the polymerization batch. A disadvantage of this process is the exudation of the polyalkylene glycols on the finished part.

The use of polymeric activators made from polyetherols and an excess of diisocyanate (prepolymeric isocyanates) is e.g. in Applied Macromolecular Chemistry 58/59 (1977), pp. 321-343. With this process, however, insufficient conversions of the lactam to the polymer are achieved, in particular with the very short polymerization times that must be observed for the RIM process.

DE-A 24 12 106 reports on block polymers made from polyether and lactam, linked via esteramide bridges. However, this process is technically very complex, and it is also necessary to work under process conditions which dictate the most embarrassing exclusion of moisture from the processor.

It is known that polyamides produced by hydrolytic polymerization can be impact-modified by adding graft polymers based on ethylene polymers (see, for example, EP-2,761). However, the graft polymers described there are not suitable for impact modification of alkaline polymerized polylactam: the graft co polymers are either insoluble in monomeric lactam or they interfere with the polymerization.

The object of the present invention was to develop a method for producing impact-resistant polyamide molding compositions, in particular for RIM technology, which overcomes the disadvantages described above.

This object is achieved by the method according to the invention.

This gives polyamide molding compositions which are notable for high impact strength, low-temperature impact strength and elongation at break and at the same time do not have the disadvantages of the processes according to the prior art described above.

• Als Polymerisate (A) kommen Naturkautschuk sowie handelsübliche synthetische Kautschuke infrage, wie sie z.B. in "The Synthetic Rubber Manual", 8th Edition, 1980, des International Institute of Synthetic Rubber Producers Inc. aufgeführt sind. Als Verbindungsklassen seien genannt Polydien-, Polychloropren-, Polybutyl-, Polynitril-, Ethylen--h-Olefin-Dien- (EPDM-) Kautschuke sowie statistische Copolymerisate aus Dienen und copolymerisierbaren Vinylmonomeren wie SBR-Kautschuke, Polyacrylatkautschuke und Ethylen-Vinylestercopolymerisate. Bevorzugt sind Dienpolymere, wie Polydiene, Polydien-Blöcke enthaltende Blockpolymere, besonders mit aus Styrol - und/oder Acrylnitril - sowie aus Butadien und/oder Isopren aufgebauten Blöcken, weiterhin SBR- und EPDM-Kautschuke. Das Molekulargewicht geeigneter Kautschuke (A) kann in weiten Grenzen variiiert werden, zu hohe Molekulargewichte führen jedoch zu entsprechend hohen Lösungsviskositäten bzw. niedrigen Konzentrationen bei der Verarbeitung. Bevorzugt werden Kautschuke mit Molekulargewichten von 500 bis 500 000, besonders bevorzugt solche, deren Molekulargewichte 2 000 bis 300 000 betragen. Als kautschukartige Polymere A können auch vernetzbare bzw. pfropfaktive, bei Raumtemperatur flüssige Polymere, z.B. Polybutadienöle, Polyisoprene oder Polydienblöcke enthaltende Blockcopolymerisate verwendet werden, deren Molekulargewichte 500 bis 5 000 betragen. In der Regel werden Kautschuke mit Glastemperaturen unter 0°C verwendet, bevorzugt solche, deren Glastemperaturen unter -10°C liegen. Dies gilt bei den Blockpolymerisaten für die jeweiligen Polydien-Blöcke. Bei der Verwendung mehrerer Kautschuke werden bevorzugt Gemische aus hoch- und niedermolekularen Polymeren A eingesetzt.

The following must be stated in detail about the starting materials for the graft polymers P:

• Suitable polymers (A) are natural rubber and commercially available synthetic rubbers, as are listed, for example, in "The Synthetic Rubber Manual", 8th Edition, 1980, of the International Institute of Synthetic Rubber Producers Inc. Polydiene, polychloroprene, polybutyl, polynitrile, ethylene-h-olefin-diene (EPDM) rubbers and statistical copolymers of dienes and copolymerizable vinyl monomers such as SBR rubbers, polyacrylate rubbers and ethylene-vinyl ester copolymers are mentioned as compound classes. Diene polymers, such as polydienes, block polymers containing polydiene blocks, in particular with blocks composed of styrene and / or acrylonitrile and of butadiene and / or isoprene, and SBR and EPDM rubbers are preferred. The molecular weight of suitable rubbers (A) can be varied within wide limits, but too high molecular weights lead to correspondingly high solution viscosities or low concentrations during processing. Rubbers with molecular weights of 500 to 500,000 are preferred, particularly preferably those whose molecular weights are 2,000 to 300,000. Crosslinkable or graft-active polymers which are liquid at room temperature, for example polybutadiene oils, polyisoprene or polydiene blocks, and block copolymers whose molecular weights are from 500 to 5000 can also be used as rubber-like polymers A. As a rule, rubbers with glass transition temperatures below 0 ° C are used, preferably those with glass transition temperatures below -10 ° C. This applies to block polymers for the respective polydiene blocks. When using several rubbers, mixtures of high and low molecular weight polymers A are preferably used.

Another preferred embodiment of the process provides for the use of rubbers which carry reactive groups with acidic hydrogen atoms, such as hydroxyl, primary or secondary amino groups, carboxyl groups.

The proportion of rubbers (A) depends on the desired degree of elasticization and the necessary proportions of starting materials (B) and possibly (C). Up to 80% by weight (A), based on the sum of (A), (B) and optionally (C), is preferably used, particularly preferably 25 to 75% by weight (A), in particular 40 to 75% by weight (A ).

Group (B) feedstocks are polyadducts, polycondensates or acrylic polymers. They should preferably be soluble in monomeric lactam and compatible with polylactam and have a molecular weight of 1000 to 50,000, preferably 1000 to 40,000, in particular 2000 to 20,000. Too low molecular weights of the polymers (B) usually have an insufficient effect with regard to compatibility with polyamide, molecular weights above 50,000 often lead to very high viscosities during processing.

Polymers (B) which have a sufficiently high grafting activity with respect to the vinyl monomers (C) are preferred, in particular those which have an average content of olefinic double bonds per polymer molecule of 0.2 to 2, preferably 0.5 to 1.3. It is optimal to use polymers that carry one olefinic double bond per molecule, but this is usually not necessary. If the double bond content is too high, undesirable crosslinking can occur. Suitable polymers (B) can in principle be all polymers which meet the above requirements and can be reacted in a homogeneous or heterogeneous reaction with the rubbers (A) and possibly the monomers (C). It is generally desirable, but not absolutely necessary, for the polymers (B) to be completely converted. Examples of suitable classes of compounds are polyadducts and polycondensates, such as polyethers, in particular polyalkylene oxides, polyesters, polyurethanes, polyether urethanes, polyester urethanes, polyamides, polyether amides and polysulfones, and also acrylic polymers with a glass transition temperature above 0 ° C., such as poly (meth) acrylic acid esters and their copolymers with other vinyl monomers and poly (meth) acrylonitrile. Preferred polymers (B) which contain olefinic double bonds can be obtained by reacting saturated polymers with olefinically unsaturated reagents. For example, polymers containing hydroxyl, primary or secondary amino groups with olefinically unsaturated carboxylic acids such as (meth) acrylic acid, maleic acid, fumaric acid or crotonic acid or its derivatives such as acid halides, anhydrides, (semi) esters. Possibly. polymers containing H-acidic groups can also be reacted with olefinically unsaturated epoxides such as glycidyl allyl ether or - (meth) acrylate or olefinically unsaturated isocyanates. Another possibility is to react polymers containing H-acidic groups with diisocyanates and H-acidic olefinically unsaturated reagents. Polymers with carboxyl groups can also be reacted with dienes capable of addition or olefinically unsaturated alcohols. However, it is also possible to use olefinically unsaturated reagents directly in the preparation of the polymers, e.g. B. olefinically unsaturated carboxylic acids in the production of polyesters or polyamides, olefinically unsaturated alcohols in the production of polyesters, polyethers, polyurethanes. In the ionic polymerization of (meth) acrylonitrile or (meth) acrylic esters, olefinically unsaturated chain termination reagents such as allyl bromide, glycidyl allyl ether or - (meth) acrylate can be used. Chain terminators or chain transfer agents which have reactive groups which can be subsequently reacted with olefinically unsaturated reagents can also be used in the polymerization.

The proportion of polymers (B) in the graft polymers P depends essentially on how much is necessary in order to achieve sufficient compatibility in each case. The graft polymers preferably contain 10 to 60% by weight of polymers (B), particularly preferably 15 to 40% by weight (B).

In principle, all radical-polymerizable compounds which have at least one vinyl double bond are suitable as monomers (C), the proportion of polyolefinically unsaturated monomers expediently being kept below 10% by weight, based on (C), in order to avoid undesired crosslinking to avoid.

Monomers which contain no functional groups are preferably used. These include olefins with 2 to 20 C atoms, vinyl aromatics with 8 to 12 C atoms, (meth) acrylic acid esters of straight-chain, branched, cycloaliphatic and araliphatic alcohols with 1 to 20 C atoms, vinyl esters of carboxylic acids with 1 to 20 C atoms , (Meth) acrylonitrile, vinyl and allyl ethers with 3 or 4 to 20 C atoms, maleic or fumaric diesters of alcohols with 1 to 20 C atoms.

It may be useful to use monomers (C ') containing functional groups in addition, the proportion of which, based on the sum (A) + (B) + (C), should generally remain below 10% by weight. About these monomers Examples include monomers containing hydroxyl groups, such as hydroxyethyl, propyl or butyl (meth) acrylate, allyl alcohol or monoallyl ethers of polyhydric alcohols, olefinically unsaturated carboxylic acids with 3 to 6 carbon atoms such as (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid and the half esters of dicarboxylic acids, epoxy compounds such as glycidyl (meth) acrylate or glycidyl allyl ether. Nitrogen-containing functional monomers, such as (meth) acrylamide and their N-alkyl derivatives, vinylpyridine, N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylformamide, dialkylaminoalkyl (meth) acrylates, vinyl or allyl ethers, and N- (meth -) Acryloyllactame.

Preferred monomers (C) are vinyl aromatics, in particular styrene, methylstyrene or vinyltoluene, and (meth) acrylic esters of alkanols containing 1 to 8 C atoms, especially methyl, ethyl, n- and i-butyl, 2-ethylhexyl (meth ) acrylate, also used vinyl acetate and propionate.

The proportion of the monomers (C), based on the sum of (A), (B) and (C), can vary within wide limits. To prepare graft polymers P from those prepolymers B which alone do not have sufficient reactivity with respect to the polymers A, it is necessary to use vinyl monomers C and C '. At least 1% by weight of monomers (C) are preferably used. The upper limit of the proportion of monomers (C) depends essentially on the choice of the proportions of rubber (A) and polymer (B). The graft polymers P preferably contain up to 50% by weight of monomers (C).

• A'. 5 bis 95 Gew.-Teilen kautschukartige Polymerisate mit einer Glastemperatur unter 0°C bildenden Monomeren,
• B. 95 bis 5 Gew.-Teilen eines monoolefinische Doppelbindungen enthaltenden Polyaddukts oder Polykondensats mit einer Glastemperatur über 0°C, sowie ggf.
• C. 0 bis 90 Gew.-Teilen Vinylmonomeren.

The process according to the invention can also be carried out in the presence of copolymers R. These are made by copolymerization of

• A '. 5 to 95 parts by weight of rubber-like polymers with monomers forming a glass transition temperature below 0 ° C.,
• B. 95 to 5 parts by weight of a polyadduct or polycondensate containing monoolefinic double bonds with a glass transition temperature above 0 ° C., and if appropriate
• C. 0 to 90 parts by weight vinyl monomers.

Preferred monomers A 'are diene and acrylate monomers, in particular butadiene and / or butyl acrylate.

The graft polymers P or copolymers R used according to the invention can be obtained by polymerizing the polymers (B) and optionally the monomers (C) in the presence of the rubber (A) or the monomers (A ') with the addition of compounds which break down into free radicals or by high-energy compounds Radiation are produced. The polymerization can be carried out in emulsions, suspension or, preferably, in solution or in a non-aqueous dispersion. Preferred solvents are hydrocarbons, for example toluene, xylenes, hexane, cyclohexane or gasolines with boiling ranges from 50 to 200 ^° C. Particularly preferred are solvents in which the rubbers (A) and the polymers (B) are soluble with not too high viscosities , with boiling ranges from 50 to 150 ° C. Another preferred embodiment consists in using the monomers (C) used as solvents and, if appropriate, removing the excess of such solvents by distillation.

The usual radical-decomposing compounds can be used as starters, e.g. Azo compounds such as azoisobutyronitrile, acyl peroxides such as benzoyl or lauroyl peroxide, alkyl peroxides such as t-butyl peroxide, hydroperoxides such as cumyl hydroperoxide, peresters such as t-butyl perpivalate, -peroctoate, -permeodecanoate or -perbenzoate or the corresponding t-amyl peroxide, peracid, peracid. Possibly. the addition of compounds that accelerate the decomposition of the starters (redox systems) can be useful. The starters can be used individually or in a mixture; preference is given to mixtures of starters with different half-lives.

If no monomers C or C 'were used, the graft polymers P are adducts of the polymers B with polymers A; when monomers C and C 'are used, the polymers A and B serve as the graft base, and the graft form from the monomers C and C'. The preferred olefinically unsaturated polymers B can also be polymerized in as side chains of the graft.

• A. 20 bis 89,9 Gew% eines kautschukartigen Dienpolymerisats mit einer Glastemperatur unter 0°C und einem Molekulargewicht von 500 bis 5 000, insbesondere Polybutadienölen oder Polybutadienblocke enthaltenden Blockcopolymerisaten,
• B. 10 bis 50 Gew% eines Polyalkylenoxids, Polyesters, Polyamids oder Polyurethans mit einem Molekulargewicht von 1 000 bis 40 000 und einem mittleren Gehalt an olefinischen Doppelbindungen je Polymermolekül von 0,3 bis 1,5 und
• C. 0,1 bis 40 Gew% eines Vinylmonomeren.

Particularly preferred graft polymers P which are new as such consist of

• A. 20 to 89.9% by weight of a rubber-like diene polymer having a glass transition temperature below 0 ° C. and a molecular weight of 500 to 5,000, in particular block copolymers containing polybutadiene oils or polybutadiene blocks,
• B. 10 to 50% by weight of a polyalkylene oxide, polyester, polyamide or polyurethane with a molecular weight of 1,000 to 40,000 and an average content of olefinic double bonds per polymer molecule of 0.3 to 1.5 and
• C. 0.1 to 40% by weight of a vinyl monomer.

• A. 20 bis 90 Gew% eines kautschukartigen Dienpolymerisats mit einer Glastemperatur unter 0°C und einem Molekulargewicht von 500 bis 500 000, und
• B. 10 bis 80 Gew% eines Polyalkylenoxids, Polyesters, Polyamids oder Polyurethans mit einem Molekulargewicht von 1 000 bis 40 000 und einem mittleren Gehalt an olefinischen Doppelbindungen je Polymermolekül von 0,3 bis 1,5.

Another group of preferred new graft polymers P consists of

• A. 20 to 90% by weight of a rubber-like diene polymer with a glass transition temperature below 0 ° C. and a molecular weight of 500 to 500,000, and
• B. 10 to 80% by weight of a polyalkylene oxide, polyester, polyamide or polyurethane with a molecular weight of 1,000 to 40,000 and an average content of olefinic double bonds per polymer molecule from 0.3 to 1.5.

These graft polymers are prepared by reacting components (A) and (B) at temperatures from 150 to 300 ° C., the addition of free radical initiators and solvents being not absolutely necessary. The preparation can also be carried out by reacting component (A) with 4,0-olefinically unsaturated dicarboxylic acids or their anhydrides, in particular maleic anhydride and subsequent reaction of these maleated polymers (A) with polyetherols, polyesterols, polyurethanes or polyamide amines.

The activated anionic lactam polymerization according to the invention is carried out according to the generally known method. The preferred lactam is f-caprolactam, and pyrrolidone, capryllactam, laurolactam, oenanthlactam and the corresponding C-substituted lactams can also be used.

As a rule, the graft polymers P or R are used in proportions of 1 to 40%, preferably 5 to 30% by weight, based on the entire batch.

Activated alkaline lactam polymerization starts with two components I and II. Component I is a lactam melt that contains a catalyst, component II is a lactam melt that contains an activator.

Suitable catalysts are e.g. Alkali and alkaline earth compounds of lactams, such as sodium c-caprolactamate, or of short-chain aliphatic carboxylic acids, such as sodium or potassium formate, or of alcohols with 1 to 6 carbon atoms, such as sodium methylate or potassium tert-butoxide. Alkali or alkaline earth metal hydrides, hydroxides or carbonates can also be used, as well as Grignard compounds. The catalysts are usually used in amounts of 0.1 to 10 mo.%, Based on total lactam.

Possible activators are: N-acyl lactams, such as N-acetyl caprolactam, substituted triazines, carbodiimides, cyanamides, mono- and polyisocyanates, and masked isocyanate compounds. They are preferably used in amounts of 0.1 to 10 mol%.

The polymerization of the lactam can be carried out in the presence of conventional stabilizers. A combination of CuI and KI in a molar ratio of 1: 3, which is added to the activator-containing component II in amounts of 50 to 100 ppm of copper, based on total lactam, is particularly advantageous. Other suitable stabilizers are cryptophenols and amines.

The activator-containing component B can also contain nucleating agents, such as talc or 2,2-polyamide, in amounts of up to 2% by weight, optionally together with peroxides.

Other common additives are regulators, pigments, dyes, plasticizers, fillers, fibers, flame retardants and blowing agents.

Non-crosslinked, prepolymeric isocyanates can also be added to the activator-containing component II in amounts of 1 to 30% by weight, based on total lactam. Here are e.g. suitable substances which have been produced by chain extension of isocyanates with polyether / polyesterols. They have an isocyanate content of 0.1 to 10% by weight. They can also be reacted with the equivalent amount of polyol during the polymerization of the lactam by adding the polyol and advantageously a urethane-forming catalyst to the catalyst-containing lactam melt.

Lactam-soluble polymers such as e.g. High molecular weight polyesters, non-crosslinked polyurethanes, polytetrahydrofuran, and copolyamides produced by polycondensation are added in amounts of 1 to 30% by weight.

Components 1 and II, are intensively mixed at temperatures between 70 and 140 ° C, preferably 100-135 ⁰ C, transported into a mold and polymerized therein at temperatures between 120 and 200 ° C. The procedure used corresponds to the reaction injection molding technique which is described for polyurethanes, for example by Piechota and Röhr, in "Integral Foam", Carl-Hanser-Verlag 1975, pages 34 to 37.

Smaller plates and molded parts can be manufactured with low-pressure dosing systems, whereby the filling takes place in the open mold. It is advisable to use smaller mixing chambers with Teflon-coated surfaces and the same stirring elements.

However, the moldings according to the invention are preferably produced using a high-pressure metering system. The components are mixed here in the manner of countercurrent atomization.

The resulting semi-finished product can then be processed into the finished part by pressing, preferably above the melting point of the polyamide.

The molded articles produced by the process according to the invention are distinguished by excellent surface quality, good mechanical properties and short mold life. They are particularly suitable as molded parts for the automotive industry, for example body parts, such as fenders and doors, or for technical housing parts.

The parts and percentages given in the examples relate to the weight. The K values were measured according to Fikentscher, Cellulosechemie 13, p. 58 (1932); the further results are obtained in accordance with the DIN standards.

Examples Preparation of polymer B1

500 parts of a polyethylene oxide of 200 moles of ethylene oxide per mole of ethylene glycol, 5 parts of maleic anhydride, 5.5 parts of succinic anhydride and 100 parts of toluene are heated to 110 ^° C. for 1 hour with stirring and stirred at this temperature for a further hour. Then volatile components are removed by distillation in vacuo and the product is discharged as a melt. The number average molecular weight is 8040.

Preparation of the graft polymer P1

25 parts of a polybutadiene oil with a molecular weight of 3000 (component A), 8.3 parts of styrene (component C) and 0.05 part of Irganox (R) 1076 (antioxidant from Ciba Geigy) are stirred in a flask for 1.5 hours heated to 70 ° C, 50 parts of freshly distilled liquid ε-caprolactam are added as a solvent and the mixture is heated to 85 ° C. Then 12.5 parts of the polymer BI and 0.4 part of acryloylcaprolactam as component C 'are added, the mixture is heated to 90 ° C. and 0.06 part of a 50% strength solution of tert. Butyl peroctoate (as a polymerization initiator) in petrol for 5 minutes and allowed to stir at 88 to 90 ^° C. for a further 4.5 hours. Then 0.016 parts of hydroquinone and hydroquinone monomethyl ether are added as stabilizers and volatile components are distilled off in vacuo at 100 to 120 ° C. 3.7 parts of distillate and 92.6 parts of a solution of the graft polymer Pl in caprolactan with a solids content of 44.1% (1 hour at 120 ° C., 200 mbar) are obtained.

To clarify the structure, the product is purified by chromatography and identified by pyrolysis gas chromatogram as a polymer consisting of butadiene, ethylene glycol, styrene and acryloylcaprolactam units.

Preparation of polymer 82

A polyether with OH number 19 and number average molecular weight 3800 (vapor pressure osmometric) is produced from 2.8 parts of allyl alcohol and 200 parts of propylene oxide and ethylene oxide each using 0.1% KOH as catalyst.

Preparation of the graft polymer P2

4 parts of a polybutadiene rubber with a molecular weight of 300,000 are dissolved in 20 parts of toluene and 20 parts of styrene at room temperature. 0.06 part of Irganox 1076 is added and the mixture is heated at 80 ° C. for 1.5 hours. After stirring for a further 2 hours at 80 ° C, 2 parts of the polymer 82, after a further 30 minutes 0.015 parts of acryloyl caprolactam and 0.025 part of a 50% solution of t-butyl peroctoate in gasoline are added, the mixture is heated to 87 to 90 ° C and stirred 1 , 8 hours at this temperature. Then 0.01 parts of tert-butyl-p-cresol and 12 parts of freshly distilled liquid caprolactam are added. Then volatile components are distilled at 100 to 120 ° C up to a residual pressure of 50 mbar. 36.5 parts of distillate and 21.6 parts of a solution of the graft polymer P2 having a solids content of 45.1% are obtained.

Production of the graft polymer P3

7.2 parts of an acrylonitrile-butadiene-acrylonitrile block polymer with 80% by weight of butadiene, which contains secondary amino groups and has a molecular weight of 2200, 2.4 parts of polymer B1, 12 parts of freshly distilled ε-caprolactam, 0.014 part of Irganox 1076, 2 , 2 parts of styrene and 0.2 part of methacryloylcaprolactam are heated to 80 ° C. for 2 hours, 0.015 part of a 50% strength solution of tert-butyl perpivalate in aliphatic hydrocarbons is added with stirring, the mixture is heated to 88 to 92 ° C. and stirred 4.5 hours at this temperature. Working up is carried out as described for the production of the rubber graft polymer 1. 2.1 parts of distillate and 21.9 parts of a solution of the graft polymer P 3 with a solids content of 46.2% are obtained.

Production of the graft polymer P4

81 parts of the acrylonitrile block polymer used for the graft polymer P3 and 27 parts of the polymer 82 are heated to 225 ° C. under nitrogen and stirred for a further 4 hours at this temperature. The mixture is allowed to cool and the product is discharged as a melt.

The product had a number average molecular weight (vapor pressure osmometric) of 11,500, the elemental analysis of product obtained by reprecipitation from cold methanol showed 77.2% C, 10.3% H and 12.5% 0.

Manufacture of polyamide molded articles example 1

• 136,36 Teile Pfropfpolymerisat P1
• 63,64 Teile E-Caprolactam,
• 40,0 Teile einer 15%igen Lösung von Hexamethylendiisocyanat in Caprolactam

Composition of component I:

• 136.36 parts of graft polymer P1
• 63.64 parts of e-caprolactam,
• 40.0 parts of a 15% solution of hexamethylene diisocyanate in caprolactam

• 200 Teile Caprolactam
• 28 Teile einer 17,5%igen Lösung von Natriumlactamat in Caprolactam.

Composition of component II:

• 200 parts of caprolactam
• 28 parts of a 17.5% solution of sodium lactamate in caprolactam.

• Die Komponenten I und II wurden in einer Gießmaschine (Niederdruckmaschine) der F-Reihe (Fa. Elastogran Maschinenbau, Straßlach bei München) in einem Mischkopf (Mischtemperatur 125 bis 135°C) mit einem Aluminium-Schneckenrührer mit 8000 U/Minute gemischt. Die Ausstoßmenge bei einem Mischungsverhältnis von 1:1 betrug 19,5 g pro Sekunde. Die Mischung wurde in eine offene, auf 150°C beheizte Form gegossen. Die Entformzeit betrug 1,5 min.

Carrying out the experiment:

• Components I and II were in a casting machine (low pressure machine) of the F series (from Elastogran Maschinenbau, Straßlach) Munich) mixed in a mixing head (mixing temperature 125 to 135 ° C) with an aluminum screw stirrer at 8000 rpm. The output amount at a mixing ratio of 1: 1 was 19.5 g per second. The mixture was poured into an open mold heated to 150 ° C. The demolding time was 1.5 minutes.

• Lochkerbschlagzähigkeit (DIN 53 453) in kJ* m-²:
  • bei 23°C: nicht gebrochen
  • bei -20°C: 19
• Reißdehnung (DIN 53 455): 137 %
• Shore D-Härte (DIN 53 504): 66

Product features:

• Notched impact strength (DIN 53 453) in kJ * m- ² :
  • at 23 ° C: not broken
  • at -20 ° C: 19
• Elongation at break (DIN 53 455): 137%
• Shore D hardness (DIN 53 504): 66

Example 2

• 136,36 Teile Pfropfpolymerisat P2
• 63,64 Teile Caprolactam
• 40 Teile einer 15%igen Lösung von Hexamethylendiisocyanat in Caprolactam

Composition of component I:

• 136.36 parts of graft polymer P2
• 63.64 parts of caprolactam
• 40 parts of a 15% solution of hexamethylene diisocyanate in caprolactam

• 200 Teile Caprolactam,
• 28 Teile einer 17,5%igen Lösung von Natriumlactamat in Caprolactam.

Composition of component II:

• 200 parts of caprolactam,
• 28 parts of a 17.5% solution of sodium lactamate in caprolactam.

Carrying out the experiment as in Example 1

• Lochkerbschlagzähigkeit bei 23⁰C: 87 kJ· m-2
• bei -20°C: 12 kJ · _m-²
• Reißdehnung: 30 %
• Shore D-Härte: 70

Product features:

• Notched impact strength at 23 ⁰ C: 87 kJ · m-2
• at -20 ° C: 12 kJ · _m - ²
• Elongation at break: 30%
• Shore D hardness: 70

Example 3

• 130,43 Teile Pfropfpolymerisat P 3
• 62,57 Teile Caprolactam
• 50 Teile einer 15%igen Lösung von Hexamethylendiisocyanat in Caprolactam

Composition of component I:

• 130.43 parts of graft polymer P 3
• 62.57 parts of caprolactam
• 50 parts of a 15% solution of hexamethylene diisocyanate in caprolactam

• 207 Teile Caprolactam
• 36 Teile einer 17,5%igen Lösung von Natriumlactamat in Caprolactam.

Composition of component II:

• 207 parts of caprolactam
• 36 parts of a 17.5% solution of sodium lactamate in caprolactam.

Carrying out the experiment as in Example 1.

• Lochkerbschlagzähigkeit 23⁰C: nicht gebrochen
• -20°C: 30,7 kJ· m-2
• Reißdehnung: 107 %
• Shore D-Härte: 75

Product features:

• Notched impact strength 23 ⁰ C: not broken
• -20 ° C: 30.7 kJ · m-2
• Elongation at break: 107%
• Shore D hardness: 75

Example 4

• 60 Teile Pfropfpolymerisat P4
• 140 Teile Caprolactam
• 40 Teile einer 15 %igen Lösung von Hexamethylendiisocyanat in Caprolactam

Composition of component I:

• 60 parts of graft polymer P4
• 140 parts of caprolactam
• 40 parts of a 15% solution of hexamethylene diisocyanate in caprolactam

• 200 Teile Caprolactam
• 28 Teile einer 17,5 %igen Lösung von Natriumlactamat in Caprolactam

Component II:

• 200 parts of caprolactam
• 28 parts of a 17.5% solution of sodium lactamate in caprolactam

Carrying out the experiment as in example 1

• Lochkerbschlagzähigkeit 23°C: nicht gebrochen
• -20°C: 31kJ· m-2
• Reißdehnung: 100 %
• Shore D-Härte: 71

Product features:

• Notched impact strength 23 ° C: not broken
• -20 ° C: 31kJ.m-2
• Elongation at break: 100%
• Shore D hardness: 71

Claims (16)

1. A process for the preparation of impact-resistant polyamide molding compositions by activated alkaline polymerization of lactams, characterized in that the polymerization is carried out in the presence of a graft polymer P, in which A. 5 to 95 parts by weight of a rubber-like polymer with a glass transition temperature below 0 ° C. B. 95 to 5 parts by weight of a polyadduct, a polycondensate or an acrylic polymer, which has a glass transition temperature above 0 ° C, and optionally C. 0 to 90 parts by weight vinyl monomers
are grafted. 2. Process for the preparation of impact-resistant polyamide molding compositions by activated alkaline polymerization of lactams, characterized in that the polymerization is carried out in the presence of a copolymer R from A '. 5 to 95 parts by weight of rubber-like polymers with a glass transition temperature below 0 ° forming monomers, B. 95 to 5 parts by weight of a polyadduct or polycondensate containing olefinic double bonds with a glass transition temperature above 0 ° C, and optionally C. 0 to 90 parts by weight vinyl monomers. 3. The method according to claim 1, characterized in that the polymers A are diene polymers with a molecular weight between 500 and 500,000. 4. The method according to claim 1, characterized in that the polymers A are polybutadiene oils with a molecular weight between 500 and 5,000. 5. The method according to claim 1, characterized in that the polymers A carry reactive groups with acidic hydrogen atoms. 6. The method according to claim 2, characterized in that the monomers A 'are diene or acrylate monomers, preferably butadiene and / or butyl acrylate. 7. The method according to claim 1 or 2, characterized in that the polymers B have an average content of olefinic double bonds per polymer molecule from 0.2 to 2.0. 8. The method according to claim 1 or 2, characterized in that the polymers B are soluble in monomeric lactam and are compatible with polylactam. 9. The method according to claim 1 or 2, characterized in that the polymers B are polyethers, polyesters, polyamides or polyurethanes with a molecular weight between 1000 and 50,000. 10. The method according to claim 1 or 2, characterized in that the vinyl monomer C is styrene. 11. The method according to claim 1 or 2, characterized in that a functional group-bearing vinyl monomer C 'in amounts of less than 10% by weight, based on the sum of A + B + C, is added. 12. The method according to claim 1 or 2, characterized in that in the alkaline lactam polymerization, a component (I) containing lactam and a catalyst, and a component (II) containing lactam and an activator at 70 to 140 ° C. mixed intensively, transported into a mold and polymerized there at 120 to 200 ° C. 13. The method according to claim 12, characterized in that the polymerization is carried out according to the reaction injection molding technology. 14. The method according to claim 12, characterized in that the activator-containing component (II) is added as stabilizers cryptophenols, amines or a mixture of CuI and KI in a molar ratio of 1: 3. 15. Graft polymers A. 20 to 89.9% by weight of a rubber-like diene polymer with a glass transition temperature below 0 ° C. and a molecular weight of 500 to 5,000, B. 20 to 50% by weight of a polyalkylene oxide, polyester, polyamide or polyurethane with a molecular weight of 1,000 to 40,000 and an average content of olefinic double bonds per polymer molecule of 0.3 to 1.5 and C. 0.1 to 40% by weight of a vinyl monomer. _ 16. Graft polymers A. 20 to 90% by weight of a rubber-like diene polymer with a glass transition temperature below 0 ° C. and a molecular weight of 500 to 500,000, and B. 10 to 80% by weight of a polyalkylene oxide, polyester, polyamide or polyurethane with a molecular weight of 1,000 to 40,000 and an average content of olefinic double bonds per polymer molecule from 0.3 to 1.5.